Three-position mechanical movement



A ril 14, 1936. v o. s, FIELD 1 2,037,651

THREE-POSITION MECHANICAL MOVEMENT Filed Aug. 15, 1950 Fla-.2.

- INVENT R Patented Apr. 14, 1936 UNITED STATES 2,037,651 THREE -POIVSI%IION MECHANICAL VEM ENT

Oscar S. Field, Rochester, N. Y., assignor to General Railway Signal Company, Rochester,

Application August 15, 1930, Serial No. 475,433 3 Claims. (01. 177-327) This invention relates in general to a mechanical movement, and has more particular reference to a three-position movement for use in light signals, relays, and the like, especially as used in railway practice, with a dead beat centralization means for a neutral position.

In the operation of relays, light signals and. the like in which a member is moved from a biased central, or neutral, position to either of two extreme positions at opposite sides of the neutral position, it is desirable that the member, on returning to the neutral biased position, remain in such position without oscillating from one side to the other thereof.

In accordance with the present invention it is proposed to provide a member biased to neutral position and operated to either of two extreme positions at opposite sides of the neutral position, with the member so arranged that it is practically free from oscillation at the neutral position upon return from either of the biased positions.

More specifically, the member when driven first moves in a horizontal direction and then pivots about a center to move on an arc to one extreme position. On moving from the neutral position to the other extreme position the same operation takes place in the reverse direction, except that the arc on which it moves has a different center from the first mentioned arc. On returning from an extreme position to the neutral position, the momentum acquired by moving on the arc is dissipated during the movement in a horizontal direction, whereby there is no tendency for oscillation at the neutral position.

Further objects, purposes and characteristic features of the present invention will appear as the description progresses, reference being made to the accompanying drawing, showing, solely by 40 way of example, and in no manner in a limiting sense, one form which the invention can assume. In the drawing:-

Fig. 1 is a front elevation of a movement according to this invention.

Fig. 2 is a side elevation of the movement.

Figs. 3, 4 and 5 are fragmentary elevations of various of the parts in various operative positions.

Fig. 6 is a schematic view of the movement and a cooperating motor element.

Referring to the drawing, there is shown a support plate I, carrying a core 2, having a pole face 3, and a second core 4, having a pole face 5, for attracting an armature 6, pivoted as at I, to rock from a neutral position, as shown in Figs. 1 and 6, to either of two extreme positions at either side of the neutral position.

On the cores 2 and 4 are windings 8 and 9, which can be separately energized by means of circuits closed by any desired means, such as 5 contact l0, which can be either manually or automatically operated in any desired manner. When winding 8 is energized, armature 6 is moved clockwise, while when winding 9 is energized, it is moved counter-clockwise, the movable contact 10 fingers I I being operated in the usual manner to cooperate with the fixed contacts 12 to control any desired circuits.

Carried by the armature 6 is an upright arm l3, having at its upper end a fork l4 with spaced ends l5 and I6.

Also carried by the support plate I, is a back bracket 11 carrying three studs l3 at its upper end. On the studs l8 are spacers IQ for spacing parallel support brackets 20 constituting a support for floatingly carrying a spectacle 2| having spaced rearwardly projecting operating pins I9 and 20 Each of the members 20 has two arcuate parallel edges 22 and 23, having their centers respectively at the inner ends 24 and 25, of slots 23 and 21 formed inthe members 20.

The spectacle 2| carries pins 28 and. 29 which are received in the slots 20 and 21 to thereby floatingly support the spectacle.

The spectacle carries a plurality of color glasses, in the present case three, designated as r, y and g and colored respectively red, yellow and green, for giving various signal aspects. These color glasses are held in place in the spectacle 2| by outer clamp members 30, and a threepointed inner clamp member 3|, carried by a pin 32 extending to the rear of the spectacle, and having sleeved thereon a spring 33 for pressing the holding member 3| against the spectacle and color glasses.

With the above arrangement of parts, the color glasses can be readily removed from the spectacle by merely pressing the pin 32 so as to compress spring 33.

One movement of armature 6 to one extreme position, as, for example, against pole shoe 3, fork 14 moves to the right, as viewed in Fig. l, to operate spectacle 21 in the manner illustrated in Figs. 3-5 inclusive. On the first movement of 50 fork [4, its end l6 engages pin I9 and slides spectacle 2| horizontally, until pin 28 is positioned at the inner end 24 of slot 26. Further movement of fork M then rocks the spectacle upwardly along the arcuate edge 22, with pin 29 following 55 this edge, to the final position shown in Fig. 5 wherein the yellow color glass y, is positioned where the red color glass 1* was formerly located, to thereby change from a red to a yellow light indication, there of course being a single fixed source of light positioned to the rear of glass 1, when in its position as shown in Fig.1.

The starting, intermediate, and final positions of the arm l3, are indicated in Figs. 3-5 by the arrows bearing the letters a, b and 0 respectively.

On de-energization of winding 8, the armature 6 and its interconnected parts is biased by gravity to its neutral position, and the spectacle 20 moves, under the influence of gravity back to the position shown in Fig. 4. When the pin 29 strikes the horizontal portion of slot 21, on this return movement, the spectacle comes to rest, and there is no tendency for the spectacle to move beyond the neutral position since the pin 29 strikes the horizontal portion of the receiving slot at substantially right angles thereto.

On energization of the other windings, 9, the

operation takes place in the reverse order to that described just above, and the green color glass y is moved to assume the position shown in Fig. 1 as occupied by the red glass 1". By providing a movement wherein the spectacle, on moving from one extreme position to the other, first must move along an are, then must move, in a horizontal direction, in a straight line, and then must move along a second are having a difierent center from the first arc, there is no tendency for overrun or oscillation upon movement from an extreme position to the neutral position. The horizontal movement enforced on the spectacle results in dissipating all kinetic energy acquired by the spectacle in moving downwardly from an extreme position, to thereby prevent overrun.

The above rather specific description of one form of the present invention, is given solely by way of. illustration, and is not intended, in any manner whatsoever, in a limiting sense. Obviously, the invention can assume many different physical forms, and is susceptible of numerous modifications, and all such forms and modifications, are intended to be included in this applications as come within the scope of the appended claims.

Having described my invention, I now claim:-

1. In a light signal, in combination, a member, means causing the member to be normally biased by gravity to a neutral position, and movable to either of two extreme positions, an operator for moving the member to the extreme positions, and means constraining the member, in going from neutral to an extreme position different from that it last occupied, to first move linearly in a horizontal direction, and then upwardly along a circular are, said means including a slotted support plate, and means on the member coacting with the slot in the support plate to first cause the horizontal movement, and then the arcuate movement.

2. A slotted support plate with the two slots horizontally aligned and having open outer ends, and closed spaced inner ends, a member positioned adjacent said plate, two spaced, laterally projecting pins on said member respectively received in said slots, and spaced a greater distance apart than are the inner ends of these slots, and at least a distance equal to the distance between the inner end of one slot and the outer end of the other, and means for pushing the member sidewise to slide the pins along the slots, and then rock the member up along an arc with its center at one of said pins.

3. In a three-position light signal, in combination, a support member including a central portion and two opposed outwardly projecting side portions with fiat horizontal faces, a spectacle having three openings, two pins on the spectacle spaced apart and carried by the flat faces of the side portions of the support member with the central portion thereof between them, means biasing the spectacle to a neutral position wherein one of said openings is positioned at a given point, and operating means for pushing, at a point below the line of the pins, on the spectacle in either of two opposite directions parallel to said flat faces, to press one of said pins against said central portion, and rock the other pin along an arc with said one pin as a center, to thus position another of said openings at said given point.

OSCAR S. FIELD. 

